A ferroelectric memory (FeRAM) retains data by spontaneous polarization of a ferroelectric film used in capacitor sections. Conventionally, the capacitor sections are formed by dry etching using a reactive gas with a patterned photoresist as a mask.
Since the materials for forming the capacitor sections, in particular, platinum (Pt) and iridium (Ir) suitably used as the electrode materials exhibit low reactivity to etching gas, conventional technology has employed etching with an increased physical effect (sputter etching). In this case, by-products produced during etching are not removed in the vapor phase but are redeposited on the side wall of the resist pattern. It is very difficult to remove these redeposited by-products, which remain as a structure. As a method for preventing redeposition of by-products on the side wall of the resist pattern, a method of etching while moving the resist backward has been proposed. However, this etching method causes the sidewall of the capacitor section to be sloped, whereby a high degree integration becomes difficult.